Robot controller enclosure

ABSTRACT

An enclosure according to an embodiment includes an internal space, an opening, a connector base, and a relay cable. A robot controller is accommodated in the internal space. The opening is formed in an external wall having predetermined environmental resistance. The connector base includes a first connector for connecting an external cable for the robot controller and can be pulled out of the enclosure. The relay cable connects a connector of the robot controller and the first connector. The relay cable has a length that allows a connecting part between the first connector and the external cable to be exposed outside the external wall when the connector base is pulled out.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of theprior Japanese Patent Application No. 2013-057288, filed on Mar. 19,2013, the entire contents of which are incorporated herein by reference.

FIELD

The embodiment discussed herein is directed to an enclosure.

BACKGROUND

Robots have been applied to various industrial uses and in particularfrequently used in place of workers in adverse environments rich indust, motes, oil mist, or the like. In such environments, in order toprevent short-circuit or the like in electronic components caused by theadhesion of dust, motes, oil mist, or the like, a robot controller isgenerally incorporated in a totally enclosed enclosure for use beingisolated from the above-described ambient environments.

The temperature inside the enclosure incorporating the robot controlleris increased by heat generation from a number of electronic componentsused in the robot controller. Given this situation, the inside of theenclosure incorporating the robot controller is generally cooled tomaintain the temperature of the robot controller within a guaranteedoperation range. An enclosure that includes a cooling device andisolates a controller from an ambient environment to cool it isdisclosed in, for example, Japanese Patent Application Laid-open No.2002-135916.

However, when a cooling device and a robot controller are incorporatedin an enclosure, the internal space of the enclosure is narrow, and theinternal space itself has a complex shape. This leads to poorworkability when an external cable from a robot or the like is connectedto the robot controller incorporated in the enclosure, requiring toolsin some cases. Even when no cooling device is incorporated in theenclosure, workability remains poor.

SUMMARY

An enclosure according to an embodiment includes an internal space, anopening, a connector base, and a relay cable. A robot controller isaccommodated in the internal space. The opening is formed in an externalwall having predetermined environmental resistance. The connector baseincludes a first connector for connecting an external cable for therobot controller and can be pulled out of the enclosure. The relay cableconnects a connector of the robot controller and the first connector.The relay cable has a length that allows a connecting part between thefirst connector and the external cable to be exposed outside theexternal wall when the connector base is pulled out.

BRIEF DESCRIPTION OF DRAWINGS

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of an enclosure according to an embodiment.

FIG. 2A is a perspective view when a connector base is viewed from thefront side.

FIG. 2B is a perspective view when the connector base is viewed from therear side.

FIG. 3 is a top view illustrating an arrangement example of a groundwire.

FIG. 4 is a diagram illustrating the position relation among the groundwire and the others parts.

FIG. 5 is a diagram illustrating a modification of a pull-out amountrestricting member.

FIG. 6 is a diagram illustrating an installation example of a fixture.

DESCRIPTION OF EMBODIMENT

With reference to the attached drawings, an embodiment of the enclosuredisclosed by the present application will be described in detail. Thisinvention is not limited by the embodiment below.

First, an enclosure according to the embodiment will be described withreference to FIG. 1. FIG. 1 is a perspective view of an enclosure 10according to the embodiment. In view of making the description easy tounderstand, FIG. 1 illustrates the enclosure 10 with part of an externalwall thereof made transparent. The following description is based on theassumption that the pull-out direction of a connector base 20 is thepositive X-axis direction in the XYZ coordinate system illustrated inFIG. 1.

As illustrated in FIG. 1, the enclosure 10 has, for example, arectangular parallelepiped shape and has the internal space isolatedfrom the external space by the external wall having predeterminedenvironmental resistance. The external wall is an example of anaccommodating means. The above-described “predetermined environmentalresistance” is represented by, for example, “IP54.” The InternationalProtection (IP) Standard includes standards for the strength ofenvironmental resistance standardized by the InternationalElectrotechnical Commission (IEC). An IP rating is denoted by two signs,that is, “IP (the first sign) (the second sign).”

The first sign represents a protection rating of electric equipment andcabinets against solid foreign matters, which is represented by sevenratings from “0”, which means no protection against dust entry, to “6”,which means no dust entry inside. The second sign represents aprotection rating against water entry, which is represented by nineratings from “0”, which means no protection against water entry, to “8”,which means the optimum resistance. When no rating is determined, “X” isdenoted.

The “IP54” means that, for electric equipment and cabinets, dust enoughto inhibit the normal operation and safety of the equipment does notenter the inside thereof and that there is no adverse effect thereon bysplashes of water from various directions. The “IP2X” means that aspherical test particle having a diameter of 12.5 mm, which is about thethickness of a finger, enters the inside thereof only partially and thatno protection rating is determined for water entry.

The enclosure 10 according to the present embodiment can improve, forexample, a low protection rating of “IP2X” of a robot controller 100 toa higher protection rating, such as “IP54”, substantially. By changing asealing member such as packing, a further higher protection rating suchas “IP65” and “IP67” can be achieved.

As illustrated in FIG. 1, a heat exchanger 11 and the robot controller100 are accommodated in the internal space of the enclosure 10. Anopening 10 a is formed in part of the external wall of the enclosure 10.The opening 10 a is an example of a communicating means. The opening 10a is formed at a position opposite a connector 100 a of the robotcontroller 100. The connector base 20 of the pull-out type having ashape that closes the opening 10 a in a retracted state is provided onthe opening 10 a. The connector base 20 is an example of a closingmeans. The enclosure 10 includes a removable top plate 10 b on a surfacedifferent from the surface on which the opening 10 a is formed, anddevices including the robot controller 100 are put in and taken out withthe top plate 10 b removed.

The heat exchanger 11 is a device that performs heat exchange betweenthe external space and the internal space of the enclosure 10 whileisolating both spaces from each other. The heat exchanger 11 maintainsthe temperature inside the enclosure 10 that is increased by heatgenerated from the robot controller 100, at a temperature within aguaranteed operation range by, for example, cooling the inside of theenclosure 10.

Specifically, the heat exchanger 11 includes therein a partition 11 aisolating a space within the heat exchanger 11 that communicates withthe inside of the enclosure 10 from a space that communicates with theoutside of the enclosure 10. The heat exchanger 11 thus includes thepartition 11 a, thereby performing temperature control within theenclosure 10 while the inflow of oil mist or dust into the inside of theenclosure 10 is cut off.

The robot controller 100 is a device that controls the motion of a robot(not illustrated). As illustrated in FIG. 1, the robot controller 100includes a connector 100 a to be attached to cables that performelectric supply to the robot and signal transmission and reception withthe robot. Although two connectors 100 a are illustrated in FIG. 1, thenumber of connectors 100 a is not limited.

The connector base 20 includes a body 21 and a lid 25. The lid 25 is anexample of a lid means. The body 21 is a nearly rectangular shaped framebody having a hollow part formed through the direction of the Z-axisdrawn in FIG. 1. The body 21 thus has the hollow part formed through adirection parallel to the Z-axis, thereby not hindering the flow of airconvecting within the enclosure 10.

As illustrated in FIG. 1, the same number of relay connectors 31 as theconnectors 100 a are provided on a surface closer to the robotcontroller 100, of the body 21 of the connector base 20. The lid 25 isprovided on a surface opposite the surface on which the relay connectors31 are provided.

One surface of each of the relay connectors 31 (the negative X-axisdirection side) is connected by a relay cable 32 to the correspondingconnector 100 a of the robot controller 100. The relay cable 32 is anexample of a relaying means. The relay cable 32 and the connector 100 aof the robot controller 100 are connected through a connector 33 of therelay cable 32. The connector 33 is, for example, connected to the robotcontroller 100 with the top plate 10 b removed. The shape of theconnecting part between the relay cable 32 and the connector 33illustrated in the drawing is merely an example.

A connector 41 of an external cable 40 is connected to the other surface(the positive X-axis side) of the relay connector 31. The external cable40 is a cable that is originally connected to the connector 100 a of therobot controller 100, that is, a cable for the robot controller 100. Inother words, the connector 41 is a connector adaptable to the connector100 a of the robot controller 100.

The length of the relay cable 32 is adjusted to allow the connectingpart between the connector 41 of the external cable 40 and the relayconnector 31 to be exposed outside the enclosure 10 when the connectorbase 20 is pulled out of the enclosure 10. The external cable 40 can bethus connected and disconnected easily. Furthermore, as described above,because the body 21 of the connector base 20 includes the hallow partformed through the direction of in the Z-axis, such operations arefurther facilitated.

As illustrated in FIG. 1, the same number of openings 21 a as theexternal cables 40 are provided on the lid 25. Each of the openings 21 ahas a size that allows the connector 41 to pass therethrough. Theexternal cable 40 is inserted into the inside of the frame-like body 21through the opening 21 a.

A cable fixture 24 is attached to the external cable 40 with theconnector 41 inserted into the inside of the body 21, and the cablefixture 24 is attached to the opening 21 a in the negative X-axisdirection. The gap between the external cable 40 and the lid 25 of theconnector base 20 is thus closely and reliably sealed up.

The cable fixture 24 is preferably attached to a position such that theexternal cable 40 does not bend within the frame-like body 21. As thecable fixture 24, a bushing, a grommet, which will be described later,or the like may be used.

The relay cable 32 is, for example, a cable formed by bundling aplurality of cables and covering them with a covering member such as aheat-shrinkable tube. The connector 33 and the connector 41 have, forexample, a disconnection-proof structure such as a latch structure,which prevents their disconnection caused by vibrations or the like.

The connector base 20 and the enclosure 10 are connected by a groundwire 50. Specifically, the ground wire 50 is connected to a fixture 50 aprovided in the connector base 20 and a fixture 50 b provided on theinternal surface of the external wall of the enclosure 10.

The ground wire 50 connects the external wall of the enclosure 10 andthe connector base 20 electrically, thereby playing a role of preventingan electric shock when an operator touches the connector base 20.Although the fixture 50 a and the fixture 50 b are not limited in theirshapes as long as they provide electric connection, screws arepreferable in view of strength and operational convenience.

In the enclosure 10 according to the present embodiment, the length ofthe ground wire 50 is set to be an appropriate length, thereby avoidingload on the relay cable 32 when the connector base 20 is pulled out.

In other words, as illustrated in FIG. 1, the length of the ground wire50 is adjusted to, when the ground wire 50 is fully stretched, allow theconnecting part between the connector 41 of the external cable 40 andthe relay connector 31 to be exposed outside the enclosure 10 to preventthe relay cable 32 from being fully stretched.

Thus, the connector base 20 is prevented from being exceedingly pulledout, thereby surely preventing a break in the relay cable 32 and thedisconnection of the relay connector 31. The ground wire 50, which playsa role of electric shock prevention, reduces cost too by being used as arestricting member for the pull-out amount of the connector base 20.

Once connected to the connector 41, the connector base 20 is insertedinto the inside of the enclosure 10 through the opening 10 a of theenclosure 10 and fixed thereto. The relay cable 32 and the ground wire50 are housed within the enclosure 10 along with the insertion of theconnector base 20.

The enclosure 10 incorporating the robot controller 100 thus includesthe pull-out connector base 20 having a shape closing the opening 10 aof the enclosure 10 in the retracted state. The connector base 20includes the relay connector 31 to which the external cable 40 for therobot controller 100 is connected. The relay connector 31 is connectedto the connector 100 a of the robot controller 100 through the relaycable 32.

By using the enclosure 10, thus, it is only need to connect the externalcable 40, which is originally connected to the connector 100 a of therobot controller 100, to the relay connector 31 of the pull-outconnector base 20. The connector base 20 being pulled out of theenclosure 10 allows connection and disconnection of the external cable40 while viewing the relay connector 31. Although FIG. 1 illustrates acase where the enclosure 10 is horizontally installed, the installationdirection of the enclosure 10 is not limited to the one illustrated inFIG. 1.

The function of the heat exchanger 11 is not limited to cooling and theheat exchanger 11 may be a device having a function of maintaining thetemperature inside the enclosure 10 constant. In an environment wherethe temperature of the robot controller 100 falls under the guaranteedoperation range, for example, in cold climate areas or the like, it maybe a heating device. When the temperature control of the robotcontroller 100 is unnecessary, the heat exchanger 11 may be omitted.

The shapes of the enclosure 10, the robot controller 100, and the heatexchanger 11 may not be limited to a rectangular parallelepiped. Each ofthe robot controller 100, the heat exchanger 11, and the connector base20 may be provided plurally. The position relation between the surfaceof the robot controller 100 on which the connector 100 a is provided andthe relay connector 31 is not limited to opposite positions.

The numbers and positions of the top plate 10 b, the connector base 20,and the opening 10 a may be appropriately changed according to thenumbers and positions of the enclosure 10, the robot controller 100, andthe heat exchanger 11. The opening 10 a may be formed in the top plate10 b. The relay cable 32 is not limited to a covered cable, and thenumber of relay cables 32 may be appropriately changed according to thenumbers and shapes of the relay connector 31 and the connectors 100 a.The ground wire 50 may be provided plurally for the respective connectorbases 20.

The enclosure 10 illustrated in FIG. 1 has a sealed structure with apacking or the like on the contact surface between the removable topplate 10 b and the enclosure 10.

Next, the detailed structure of the connector base 20 will be describedwith reference to FIG. 2A and FIG. 2B. FIG. 2A is a perspective viewwhen the connector base 20 is viewed from the front side, and FIG. 2B isa perspective view when it is viewed from the rear side. The shape ofthe connecting part of the relay connector 31 illustrated in FIG. 2A andthe shape of the rear surface of the relay connector 31 illustrated inFIG. 2B are merely examples.

As illustrated in FIG. 2A, the connector base 20 includes the opening 21a in the lid 25. The opening 21 a has a size allowing the connector 41to pass therethrough. The connector base 20 includes a cable fixture 22,a cable fixture frame 23, and a packing 23 c, which are first sealingmembers, and ensures sealability of an area where the external cable 40passes through the lid 25. The first sealing members are examples of afirst sealing means. Specifically, the cable fixture 22 is formed of anelastic material such as rubber and synthetic resin and has a throughhole 22 a whose diameter is slightly smaller than the cross section ofthe external cable 40 in the central part of its rectangularparallelepiped shape.

The cable fixture 22 includes a pair of recesses on facing surfaces outof surfaces not including the through hole 22 a and includes a slit 22 bthat connects one of the surfaces including a recess and the throughhole 22 a. The external cable 40 is fitted to the through hole 22 a byallowing the external cable 40 to spread out the slit 22 b and passtherethrough. The reason why the diameter of the through hole 22 a isslightly smaller than the diameter of the external cable 40 is based onthe expectation of a sealing effect by compression, which will bedescribed later.

As the cable fixture 22 and the cable fixture frame 23, for example, agrommet may be used. The cable fixture 22 to which the external cable 40is fitted is attached to the cable fixture frame 23. The cable fixtureframe 23 has a nearly rectangular frame body and includes a hollow partto which the cable fixture 22 is attached with the surface having thethrough hole 22 a allowed to pass, and its frame part tightly covers theentire perimeter of the opening 21 a. The cable fixture frame 23includes two parts of a fitting part 23 a and a pressing part 23 b.

The fitting part 23 a is U-shaped and has protrusions corresponding tothe recesses of the cable fixture 22, on the two facing surfacesadjacent to the hollow part. The pressing part 23 b is plate-like and ispress-fixed to the fitting part 23 a by screws or the like. The materialof the cable fixture frame 23 may be any material having heatresistance, corrosion resistance, and moderate strength and ispreferably synthetic resin such as polyamide in view of ease of workingand cost.

The cable fixture 22 is attached to the fitting part 23 a by beingpressed in the negative Z-axis direction in the drawing with theprotrusions and recesses fitted to each other. Because the part of thefitting part 23 a in which the cable fixture 22 is housed is slightlysmaller than the cable fixture 22, the cable fixture 22 is attached tothe fitting part 23 a in a compressed state.

The part of the cable fixture 22 that is not housed within the fittingpart 23 a and protrudes in the Z-axis direction in the drawing iscompressed by the pressing part 23 b to be housed within the cablefixture frame 23. Because a force acts isotropically on the YZ-plane inthe drawing in a state where the cable fixture 22 is compressed to behoused within the cable fixture frame 23, the contact surface betweenthe external cable 40 and the cable fixture 22 and the contact surfacebetween the cable fixture 22 and the cable fixture frame 23 are closelysealed up.

The cable fixture frame 23 thus assembled is attached to the lid 25 inthe negative X-axis direction in the drawing, covering the opening 21 awith the packing 23 c interposed therebetween. The contact surfacebetween the cable fixture frame 23 and the lid 25 is thereby closelysealed up. As described above, it is preferable that the cable fixture22 or the like is attached to a position such that the external cable 40does not bend within the nearly rectangular frame body of the body 21.

As the material of the packing 23 c, general rubber and synthetic resinmay be used. The sealing part may have, not only a structure with theinserted packing, but also an O-ring sealed structure using the samematerial as the packing. The same applies to the packing below.

As illustrated in FIG. 2B, the connector base 20 includes a secondsealing member in an area 200 in which the lid 25 is in close contactwith the perimeter of the opening 10 a, where the second sealing memberis, for example, a packing having the same shape as the area 200. Thesecond sealing member is an example of a second sealing means. The lid25 is fastened to the enclosure 10 through the packing, thereby sealingthe area 200.

In order to ensure the sealability of the area 200, the lid 25 ispreferably strong enough to cause no strain even under a reaction forcefrom the packing when press-fixed to the enclosure 10. For this reason,the lid 25 is formed by bending both long sides of a rectangularmetallic plate in the same direction along a line by a certain distancefrom the sides. This improves the planarity of the area 200 whileensuring workability and low cost.

The lid 25 thus formed into the shape with both ends bent has theopening 21 a between the bent parts. This allows the pair of the bentparts to play a role of a guide, facilitating an operation for insertingthe connector 41 into the opening 21 a.

As illustrated in FIG. 2B, the underside of the lid 25 is positionedlower than the underside of the body 21. Then, when the connector base20 is placed on a flat surface, the connector base 20 is stable with agap produced between the connector base 20 and the surface. Thisfacilitates a connection operation of the connector 41. The lid 25 ispreferably fixed to the enclosure 10 with screws at several points,preferably four points, in view of reliable sealability and operationalconvenience.

Next, an arrangement example of the ground wire 50 will be describedwith reference to FIG. 3. FIG. 3 is a top view illustrating anarrangement example of the ground wire 50. FIG. 3 illustrates a statewhere the connector base 20 is pulled out of the enclosure 10. Asillustrated in FIG. 3, the ground wire 50 is fixed to the connector base20 and the enclosure 10 with the fixtures 50 a and 50 b, respectively,and connects the two mechanically and electrically.

As illustrated in FIG. 3, the ground wire 50 is fixed near the center ofthe connector base 20 in the Y-axis direction in the drawing. Thus, whena single ground wire 50 is used, the ground wire 50 is preferably fixednear the center of the connector base 20 in the Y-axis direction. Bydoing so, an attitude change of the pulled-out connector base 20 can bereduced, preventing only one relay cable 32 from being pulled.

The ground wire 50 is not limited in its material as long as it is aless elastic material. For example, as the ground wire 50, a generalcovered wire with a multicore copper wire as a core material and withpolyethylene or polyvinyl chloride as a covering material may be used.The fixtures 50 a and 50 b may be any members that fix the ground wire50, and, for example, screws may be used.

The ground wire 50 is in a slack state, together with the relay cable32, within the enclosure 10 when the connector base 20 is retracted, andis pulled out when the connector base 20 is pulled out. The connectorbase 20 is pulled out until the ground wire 50 is fully stretched. Asillustrated in FIG. 3, the relay cable 32 remains slack even when theground wire 50 is fully stretched.

FIG. 4 is a diagram illustrating the position relation among the groundwire 50 and the other parts. FIG. 4 schematically illustrates theposition relation among the parts when the connector base 20 is pulledout of the enclosure 10 and the ground wire 50 is fully stretched whilethe relay cable 32 is not.

It is assumed that the connector base 20 retracted in the enclosure 10is pulled out in the direction A, that is, in the positive X-axisdirection in the drawing. The distance d1 is the distance from the wallsurface of the enclosure 10 having the opening 10 a to the fixture 50 bof the ground wire 50, and the distance d2 is the distance from the wallsurface of the enclosure 10 to a connector 100 a to which the relaycable 32 is attached on the robot controller 100.

An imaginary line 321 is a straight line connecting between theattachment parts at both ends of the relay cable 32. The length L1 andL2 are the lengths of the ground wire 50 and the relay cable 32,respectively. The angle θ11 and angle θ21 are the angles that the groundwire 50 and the imaginary line 321, respectively, form with the XY-planein the drawing. The angle θ12 and angle θ22 are angles that theprojection lines of the ground wire 50 and the imaginary line 321 ontothe XY-plane in the drawing, respectively, form with the X-axis in thedrawing.

Under the foregoing conditions, when projected onto the X-axis in thedrawing, the lengths of the ground wire 50 and the relay cable 32assumed to be stretched along the imaginary line 321 are L1·cos θ11·cosθ12 and L2·cos θ21·cos θ22, respectively. Then, as illustrated in FIG.4, for a state where only the ground wire 50 is fully stretched, thefollowing Formula (1) needs to be satisfied:L1·cos θ11·cos θ12−d1<L2·cos θ21·cos θ22−d2  (1)

In other words, if Formula (1) is satisfied, when the connector base 20is pulled out, the ground wire 50 fully stretched while the relay cable32 is not prevents the relay cable 32 from being pulled out further.Then, having an extra length along the imaginary line 321 and receivingno tensile tension when the ground wire 50 is fully stretched, the relaycable 32 is prevented from being broken.

By setting L1 to be a certain value or less that satisfies Formula (1)and restricting the pull-out amount of the connector base 20 to be acertain amount or less, a break in the relay cable 32 caused by pinchingis prevented. For the enclosure 10, for example, by setting the L1·cosθ11·cos θ12 to be nearly zero or a negative value with Formula (1)satisfied, the gap between the opening 10 a and the connector base 20when the connector base 20 is fully pulled out disappears. This preventsthe relay cable 32 from being exposed outside the enclosure 10, therebyavoiding the relay cable 32 from being pinched when the connector base20 is pulled out or retracted.

Thus, when the length of the ground wire 50 is determined so that apredetermined condition is satisfied, a break in the relay cable 32caused by pulling and pinching is prevented. Thus, in the enclosure 10according to the present embodiment, the ground wire 50 used in view ofelectric shock prevention is also provided with a role as the pull-outamount restricting member for the connector base 20. Depending on thepositions of the heat exchanger 11, the robot controller 100, theconnector 100 a on the robot controller 100, and the like, the pull-outdirection of the connector base 20, or the like, the length of theground wire 50 is appropriately changed.

Next, a modification of the pull-out amount restricting member will bedescribed with reference to FIG. 5. FIG. 5 is a diagram illustrating themodification of the pull-out amount restricting member. The drawingillustrates an example where the pull-out amount of the connector base20 is restricted by the ground wire 50 and a predetermined couplingmember 51. FIG. 5 illustrates a state where the connector base 20 ispulled out of the enclosure 10.

As illustrated in FIG. 5, the coupling member 51 has the same length asthe ground wire 50 and is fixed to the enclosure 10 and the connectorbase 20 through a fixture 51 a and a fixture 51 b, respectively. Thefixture 51 a and the fixture 51 b are preferably, for example, screws inview of mechanical strength and operational convenience. The couplingmember 51 and the ground wire 50 are arranged spaced apart from eachother symmetrically with respect to a plane B that passes through theopening surface of the connector base 20, is perpendicular to thesurface, and is parallel to the XZ-plane in the drawing.

The coupling member 51, as long as it is wire-like, may be formed of anymaterial that has high tensile strength in the wire direction,flexibility, and no elasticity. It may be, for example, the same as theground wire 50. A member having a structure of a rail, a stretchableshaft, or the like may be used. A case where a wire-like member is usedwill be described.

When the connector base 20 is pulled out of the enclosure 10, thesymmetrically arranged coupling member 51 and ground wire 50 are fullystretched simultaneously, and the connector base 20 is supported atmultiple points. When supported at multiple points, the connector base20 is prevented from rotating about the wire direction of the groundwire 50 and rotating with the center being the fixture 50 a and theradius being the length from the fixture 50 a to the position where thelid 25 is supported. Consequently, the attitude is stabilized. Thestabilization of the attitude of the connector base 20 by themulti-point support is obtained for any pull-out direction of theconnector base 20 depending on the installation direction of theenclosure 10.

Thus, the enclosure illustrated in FIG. 5 includes, in addition to theground wire 50, the coupling member 51 that has the same length as theground wire 50 and is arranged spaced apart therefrom symmetrically withrespect to the plane perpendicular to the opening surface of theconnector base 20. This allows the connector base 20, when it is fullypulled out, to be supported at the multiple points, stabilizes itsattitude, and prevents a break in the relay cable 32 caused by pullingdue to the rotation of the connector base 20. Either one of or both ofthe ground wire 50 and the coupling member 51 may be provided plurally.

Next, a fixture 60 of the relay cable 32 will be described withreference to FIG. 6. FIG. 6 is a diagram illustrating an installationexample of the fixture 60, and in view of making the description easy tounderstand, illustrates the enclosure 10 with part of the external wallthereof made transparent.

Each of the relay cables 32 can move with a connecting point with theconnector 33 as the fulcrum. A cable 322 indicated by broken lines inFIG. 6 schematically illustrates that the relay cable 32 can move.Because these relay cables 32 move in this way, they are expected to belifted in the Z-axis direction in the drawing, to be twisted, and to getentangled with each other, when the connector base 20 is put in andtaken out.

Then, as illustrated in FIG. 6, with the fixture 60 that holds the relaycable 32 inside the enclosure 10 provided, the movement of the relaycables 32 can be suppressed. The fixture 60 includes a holding part thatholds the relay cable 32 and a fixing part that fixes the fixture 60 tothe inside of the enclosure 10. The fixture 60 may be, for example, acable tie made of synthetic resin such as polyethylene, polypropylene,and nylon or a metallic member such as iron.

The holding part holds the relay cable 32, fixes the relay cable 32 tothe holding part, and prevents the rotational movement of the relaycable 32 about the wire direction. The fixing part fixes the holdingpart to the wall surface of the enclosure 10. Although the fixing mannerof the fixing part is not limited, screws are preferable in view ofmechanical strength and operational convenience.

As illustrated in FIG. 6, the fixture 60 is arranged inside theenclosure 10 near the connecting part between the connector 33 and theconnector 100 a. Depending on the position relation among the connectorbase 20, the connector 100 a, or the like, the fixture 60 may also befixed to any part other than the wall surface of the enclosure 10. Therelay cable 32 is fixed near the connecting part between the connector33 and the connector 100 a with the fixture 60, thereby cutting off, atthe holding part, a force caused by the uncontrolled movement of therelay cable 32.

In other words, the force caused by the uncontrolled movement of therelay cable 32 does not act on the connector 33, and the disconnectionof the connector 33 from the connector 100 a is prevented. Owing to thefixture 60, the holding part as a fixed point near the wall surfaceserves as the fulcrum of the flexural movement of the relay cable 32when the connector base 20 is put in and taken out. The holding partprevents the lifting of the relay cable 32 from the wall surface causedwhen the connector base 20 is put in and taken out, making the relaycables 32 less likely to be twisted and to get entangled with eachother.

The fixture 60 thus prevents the disconnection of the connector 33 orthe like caused by vibrations and a break in the relay cables 32 causedby the entanglement and twisting of the relay cables 32, whereby theconnector base 20 is smoothly put in and taken out. Depending on thepositions of the heat exchanger 11, the robot controller 100, theconnector 100 a on the robot controller 100, and the like, the pull-outdirection of the connector base 20, or the like, the position and thenumber of the fixture 60 for the relay cable 32 may be appropriatelychanged.

As described above, the enclosure according to the embodiment includesthe internal space, the openings, the connector base, and the relaycables. The internal space accommodates the robot controller. Theopenings are formed in part of the external wall having predeterminedenvironmental resistance. The connector base can be pulled out of theenclosure, includes the relay connector (the first connector) forconnecting the external cable for the robot controller, and has a shapethat covers the opening in the retracted state. The relay cable connectsthe second connector as the connector of the robot controller and therelay connector. The relay cable has a length that allows the connectingpart between the relay connector and the external cable is exposedoutside the enclosure with the connector base being pulled out.

The enclosure according to the embodiment can therefore allow easy andsecure connection of the cable from the outside of the enclosure to therobot controller incorporated in the enclosure.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. An enclosure comprising: an internal space thataccommodates therein a robot controller; an opening that is formed inpart of an external wall having predetermined environmental resistance;a pull-out connector base that comprises a first connector forconnecting an external cable for the robot controller and closes theopening in a retracted state; and a relay cable that connects a secondconnector as a connector of the robot controller and the firstconnector, wherein the relay cable has a length that allows a connectingpart between the first connector and the external cable to be exposedoutside the external wall when the pull-out connector base is pulledout, wherein the enclosure further comprises a ground wire whose baseend is fixed to an internal surface of the external wall and the otherend is connected to the pull-out connector base, and wherein the groundwire has a length that allows the ground wire to be fully stretchedwhile the relay cable is not when the pull-out connector base is pulledout.
 2. The enclosure according to claim 1, wherein the pull-outconnector base has a nearly rectangular frame body in the top view. 3.The enclosure according to claim 2, wherein the pull-out connector basefurther comprises a lid that closes the opening in the retracted state,the first connector is provided on a side of the frame body on the robotcontroller side, the lid is provided on a side opposite the side on therobot controller side, and the lid comprises first sealing members thatmaintain sealability between the external cable connected to the firstconnector and the lid.
 4. The enclosure according to claim 3, whereinthe lid is formed by bending both long sides of a rectangular metallicplate in the same direction along a line by a certain distance from thesides, and the lid has a surface opposite the bending direction thatmakes contact with the external wall in the retracted state.
 5. Theenclosure according to claim 3, wherein the lid further comprises asecond sealing member on a part that is in close contact with theexternal wall in the retracted state.
 6. The enclosure according toclaim 4, wherein the lid further comprises a second sealing member on apart that is in close contact with the external wall in the retractedstate.
 7. The enclosure according to claim 1, further comprising afixture that fixes the relay cable to the internal surface of theexternal wall near the second connector.
 8. An enclosure comprising: aninternal space that accommodates therein a robot controller; an openingthat is formed in part of an external wall having predeterminedenvironmental resistance; a pull-out connector base that comprises afirst connector for connecting an external cable for the robotcontroller and closes the opening in a retracted state; and a relaycable that connects a second connector as a connector of the robotcontroller and the first connector, wherein the relay cable has a lengththat allows a connecting part between the first connector and theexternal cable to be exposed outside the external wall when the pull-outconnector base is pulled out, wherein the pull-out connector base has anearly rectangular frame body in the top view, wherein the pull-outconnector base further comprises a lid that closes the opening in theretracted state, wherein the first connector is provided on a side ofthe frame body on the robot controller side, wherein the lid is providedon a side opposite the side on the robot controller side, wherein thelid comprises first sealing members that maintain sealability betweenthe external cable connected to the first connector and the lid, andwherein the lid is formed by bending both long, sides of a rectangularmetallic plate in the same direction along a line by a certain distancefrom the sides, and the lid has a surface opposite the bending directionthat makes contact with the external wall in the retracted state.
 9. Theenclosure according to claim 8, wherein the lid further comprises asecond sealing member on a part that is in close contact with theexternal wall in the retracted state.
 10. The enclosure according toclaim 8, further comprising a fixture that fixes the relay cable to theinternal surface of the external wall near the second connector.